Symfony2 many-to-many self referencing relation using Doctrine2
Symfony\Component\Security\Core\Authentication\Token\UsernamePasswordToken::serialize() must return a string or NULL
I created this blog because I wanted to help others who are self learners like me. I spent few hours to figure out why I was getting the next error when playing with Symfony2.Symfony\Component\Security\Core\Authentication\Token\UsernamePasswordToken::serialize() must return a string or NULL
I had an User entity a many to many self referencing relation. I still did not find out why I was getting the error but I found out here a way to get rid of the error. I just had to add the __sleep method for the user entity like this:
/**
* @ORM\Entity(repositoryClass="Acme\DemoBundle\Repository\UserRepository")
* @ORM\Table(name="users")
* @ORM\HasLifecycleCallbacks()
*/
class User
{
/**
* @ORM\Id
* @ORM\Column(type="integer")
* @ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
..................
public function __sleep()
{
return array('id');
}
}
I hope this helped someone who got the same error as I did. If you have a better solution please post it here.
